Commit | Line | Data |
---|---|---|
3d2f30a1 PNA |
1 | /* |
2 | * Copyright (c) 2016 Pablo Neira Ayuso <pablo@netfilter.org> | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License version 2 as | |
6 | * published by the Free Software Foundation. | |
7 | */ | |
8 | ||
9 | #include <linux/kernel.h> | |
10 | #include <linux/init.h> | |
11 | #include <linux/module.h> | |
12 | #include <linux/atomic.h> | |
13 | #include <linux/netlink.h> | |
14 | #include <linux/netfilter.h> | |
15 | #include <linux/netfilter/nf_tables.h> | |
16 | #include <net/netfilter/nf_tables.h> | |
17 | ||
18 | struct nft_quota { | |
19 | u64 quota; | |
20 | bool invert; | |
21 | atomic64_t remain; | |
22 | }; | |
23 | ||
22609b43 PNA |
24 | static inline bool nft_overquota(struct nft_quota *priv, |
25 | const struct nft_pktinfo *pkt) | |
3d2f30a1 | 26 | { |
22609b43 | 27 | return atomic64_sub_return(pkt->skb->len, &priv->remain) < 0; |
3d2f30a1 PNA |
28 | } |
29 | ||
30 | static void nft_quota_eval(const struct nft_expr *expr, | |
31 | struct nft_regs *regs, | |
32 | const struct nft_pktinfo *pkt) | |
33 | { | |
34 | struct nft_quota *priv = nft_expr_priv(expr); | |
35 | ||
22609b43 | 36 | if (nft_overquota(priv, pkt) ^ priv->invert) |
3d2f30a1 PNA |
37 | regs->verdict.code = NFT_BREAK; |
38 | } | |
39 | ||
40 | static const struct nla_policy nft_quota_policy[NFTA_QUOTA_MAX + 1] = { | |
41 | [NFTA_QUOTA_BYTES] = { .type = NLA_U64 }, | |
42 | [NFTA_QUOTA_FLAGS] = { .type = NLA_U32 }, | |
43 | }; | |
44 | ||
45 | static int nft_quota_init(const struct nft_ctx *ctx, | |
46 | const struct nft_expr *expr, | |
47 | const struct nlattr * const tb[]) | |
48 | { | |
49 | struct nft_quota *priv = nft_expr_priv(expr); | |
50 | u32 flags = 0; | |
51 | u64 quota; | |
52 | ||
53 | if (!tb[NFTA_QUOTA_BYTES]) | |
54 | return -EINVAL; | |
55 | ||
56 | quota = be64_to_cpu(nla_get_be64(tb[NFTA_QUOTA_BYTES])); | |
57 | if (quota > S64_MAX) | |
58 | return -EOVERFLOW; | |
59 | ||
60 | if (tb[NFTA_QUOTA_FLAGS]) { | |
61 | flags = ntohl(nla_get_be32(tb[NFTA_QUOTA_FLAGS])); | |
62 | if (flags & ~NFT_QUOTA_F_INV) | |
63 | return -EINVAL; | |
64 | } | |
65 | ||
66 | priv->quota = quota; | |
67 | priv->invert = (flags & NFT_QUOTA_F_INV) ? true : false; | |
68 | atomic64_set(&priv->remain, quota); | |
69 | ||
70 | return 0; | |
71 | } | |
72 | ||
73 | static int nft_quota_dump(struct sk_buff *skb, const struct nft_expr *expr) | |
74 | { | |
75 | const struct nft_quota *priv = nft_expr_priv(expr); | |
76 | u32 flags = priv->invert ? NFT_QUOTA_F_INV : 0; | |
77 | ||
78 | if (nla_put_be64(skb, NFTA_QUOTA_BYTES, cpu_to_be64(priv->quota), | |
79 | NFTA_QUOTA_PAD) || | |
80 | nla_put_be32(skb, NFTA_QUOTA_FLAGS, htonl(flags))) | |
81 | goto nla_put_failure; | |
82 | return 0; | |
83 | ||
84 | nla_put_failure: | |
85 | return -1; | |
86 | } | |
87 | ||
88 | static struct nft_expr_type nft_quota_type; | |
89 | static const struct nft_expr_ops nft_quota_ops = { | |
90 | .type = &nft_quota_type, | |
91 | .size = NFT_EXPR_SIZE(sizeof(struct nft_quota)), | |
92 | .eval = nft_quota_eval, | |
93 | .init = nft_quota_init, | |
94 | .dump = nft_quota_dump, | |
95 | }; | |
96 | ||
97 | static struct nft_expr_type nft_quota_type __read_mostly = { | |
98 | .name = "quota", | |
99 | .ops = &nft_quota_ops, | |
100 | .policy = nft_quota_policy, | |
101 | .maxattr = NFTA_QUOTA_MAX, | |
102 | .flags = NFT_EXPR_STATEFUL, | |
103 | .owner = THIS_MODULE, | |
104 | }; | |
105 | ||
106 | static int __init nft_quota_module_init(void) | |
107 | { | |
108 | return nft_register_expr(&nft_quota_type); | |
109 | } | |
110 | ||
111 | static void __exit nft_quota_module_exit(void) | |
112 | { | |
113 | nft_unregister_expr(&nft_quota_type); | |
114 | } | |
115 | ||
116 | module_init(nft_quota_module_init); | |
117 | module_exit(nft_quota_module_exit); | |
118 | ||
119 | MODULE_LICENSE("GPL"); | |
120 | MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>"); | |
121 | MODULE_ALIAS_NFT_EXPR("quota"); |